The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2012
Filed:
Apr. 05, 2010
Tetsuya Tokoro, Ichinomiya, JP;
Yukihiko Shigeoka, Ogaki, JP;
Hisao Ito, Saitama, JP;
Hideo Yoshida, Saitama, JP;
Takezo Nagamitsu, Saitama, JP;
Tetsuya Tokoro, Ichinomiya, JP;
Yukihiko Shigeoka, Ogaki, JP;
Hisao Ito, Saitama, JP;
Hideo Yoshida, Saitama, JP;
Takezo Nagamitsu, Saitama, JP;
Abstract
Abnormal noise generated while driving a piezoelectric actuator is prevented. A pulse-generation circuit is capable of selectively generating a displacement pulse and a stationary pulse as a drive pulse for application to a piezoelectric element, the displacement pulse having a duty ratio for causing a lens to be displaced by a predetermined step width, and the stationary pulse having a duty ratio for causing the lens to remain stationary in a current position. The pulse-generation circuit controls the production of the drive pulse continuously for a plurality of times within the servo control cycle, causes the displacement pulse to be produced when the remainder of a required amount of displacement is equal to or greater than a threshold value, and causes the stationary pulse to be continuously produced until the initiation of the next servo control cycle when the remainder is less than the threshold value.